1. Field of the Invention
The invention relates to monitoring, recording and analyzing telephone subscriber line activity, and more particularly, to determining the adequacy of the current level of subscriber service and service options.
2. Background
The telephone industry is constantly developing new service options in an attempt to improve the service provided to its customers and subscribers. The variety of subscriber service options available is considerable.
In most cases, a subscriber is provided telephone service by a local service provider. The most basic and economical service offered by the service provider is a single subscriber line. A single subscriber line can only support a single user at any one time. Thus, if someone is using the line, and an individual attempts to call the line, the caller will receive a busy signal. This results in a missed call. For a business entity, this may result in a lost customer or sale.
Since the entire purpose of a telephone system is to allow communication of one sort or another, service providers and telephone equipment manufacturers have devised a number of systems, with a variety of service options, that help to reduce the number of missed calls.
The oldest way of reducing the number of missed calls is to install multiple subscriber lines for a given phone number. When a first subscriber line is busy with a first call, a second incoming call to the phone number is routed to a second subscriber line. However, a missed call is still possible in a two-line phone installation if a third incoming call is attempted. Therefore, the solution would be to add still more phone lines to reduce the possibility of a missed call. This practice rapidly becomes uneconomical.
Today a common custom subscriber service is `call waiting`. This feature is implemented at the local switch. This service option allows a customer to place an active call on hold, answer an incoming call and conduct a conversation with another party, and then resume the first conversation with the original party. As a result of installing this service option, the number of missed calls can be reduced to some degree. However, if several calls are placed to an active, off-hook subscriber line at the approximately the same time, call waiting will not prevent the occurrence of missed calls. In addition, call waiting is of no help when the subscriber line is unattended.
Another common service option, which is again offered by service providers and supported on typical exchange/switch systems, is `voice mail`. A voice mail system provides a caller the option of leaving a message if the subscriber cannot or does not answer the line at the time the call is placed. As a result, the call can be `received` and a response such as a return call can be made to the caller. Thus, a missed call is avoided.
The above mentioned service options are among the most popular offered by service providers. There are others, such as "call forwarding" and "transfer on busy". New service options are continually being devised, implemented, and offered to subscribers. For an additional fee, they provide enhanced service capability and will very often reduce the number of missed calls. Reducing the number of missed calls is a critical consideration for companies, large and small, who rely on their telephone service to conduct business with their customers.
It is important to note, however, that a key problem has not been addressed in the industry. How does a subscriber know when the current level of service being purchased is inadequate?. Also, how does a customer determine if the fee charged for the service option is justified by its benefit? From the service provider's standpoint, this is a marketing question. That is, if a system or method can be implemented to statistically demonstrate the inadequacy of the current service, it would allow the service provider to clearly justify to the subscriber the need for additional service options and/or lines. This would lead to the generation additional revenue for the service provider, and most likely for the subscriber as well. In particular, an approach which does not require expensive additional hardware is most desirable.
Services such as call waiting, voice mail, call forwarding, and others, are implemented within the telephone switching system itself. A switching system gets its functional capabilities from a software package generically called a switching system program. It is a large, real-time, long-lived, and frequently modified multi-module program. Indeed, these programs are so complex that they are modified under the control of other very large and complicated programs called version control software. As an example, AT&T has a version control program, which is called Extended Change Management System, or ECMS, that tracks all changes made to the switching system program. This tracking program is used so that any change to the switch program that does not work or introduces problems can be backed out of to a previous version. This particular tracking system can track and save the change history for multiple versions, concurrently. The switching system programs are generally run under a real-time, multi-tasking, and multi-user operating system. The Unix Operating System is the current industry standard for telephone switching systems.
A typical AT&T switch installation uses a 4ESS or 5ESS switching system. These switching systems currently utilize the System V version of Unix as their operating system. They are specifically designed with the intent of adding features and capabilities not yet envisioned or available at the time they are brought on-line. This is evidenced by the inclusion of the ECMS version control software development tools in the overall system package.
This kind of switch architecture is flexible, configurable and expandable. These characteristics are particularly important for telephone exchange equipment. It is these characteristics which allow features and service options to be added and/or modified. They also allow the service options to be tailored to the individual subscriber.
There are numerous examples of systems that monitor line activity in the prior art. While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as hereinafter described.
U.S. Pat. No. 4,559,416 to Thesis et al, and U.S. Pat. No. 5,233,642 to Renton provide hardware separate from the service provider switch to monitor the line activity. They are either directly connected to the subscriber line, or coupled to the line with an adapter.
The Thesis patent is a portable microprocessor based system that is used to collect information and provide a profile of caller activity. The information collected is concerned with the calling party, not the called party, and does not determine information related to missed calls. Therefore this system is not at all useful in evaluating the adequacy of the current level of callee (called party) subscriber service.
The Renton patent provides another type of portable system which generates and collects call detail record information relating to the use of mobile cellular telephones. Subsequently, the collected information can be downloaded to a computer. The purpose of the system is to generate and collect call detail information that would allow records to be generated to indicate the usage of the cellular system. This includes the length of calls for outgoing and incoming calls, and the number dialed for outgoing calls. This system is not intended to, nor is it capable of, determining the number of missed calls and the adequacy of a subscriber's service.
The Renton system is one of a variety of systems known in the prior art which are concerned with call detail information, primarily for generating a calling history or billing data. These systems are not intended for the same purpose as the present invention. They require hardware not associated with a service providers switch and they are used with a particular line, or group of lines. These inventions are not at all concerned with the determination of the adequacy of a subscribers current service.
Yet another example of prior art which is concerned with call detail information is U.S. Pat. No. 5,218,632 to Cool. This system is realized using the service provider's exchange equipment, but is concerned with the details of "when" a subscriber should be billed for a call.
One final example in the prior art, U.S. Pat. No. 4,319,090 to Garwood et al, which is concerned with determining the existing service capabilities, focuses not on a subscriber's line, but instead on the exchange equipment itself. That is, the disclosure focuses on determining the capacity and capabilities of the switching system, and not that of the subscriber lines.
As stated above, what is lacking in the prior art is a system to determine when additional service is needed by subscribers by developing statistics related to missed calls for an individual subscriber. This would provide a good assessment of the current level of service, and how well that level meets the subscriber's needs.